In between these poles of mathematic as subject, as structure and as narrative construction stands the automated processes. In the last 60 years or so, computers have galvanised and specialised the precision of the relations between the abstract mathematical procedures and visual content. Indeed, it has been possible by means of automated processes, especially in the construction of geometrical operations. The rest of the article focus on structures defined on abstract art instead of figurative or narratives as in the case of Last year in Marienbad. As a result, we are interested in authorship in arts and sciences from a double perspective: as creator of an aesthetic geometrical result and as inventor of an abstract structure. A clear and simple example of such a problematic objects can be found in the Ulam spiral. Bored during a meeting Stanislaw Ulam started to organise numbers in a spiral and in this structures some patterns seem to appear for prime numbers. This simple object of number disposition leads to beautiful imagery when focusing on the prime numbers disposition and to some new mathematical results about these prime numbers.

The signature over the aesthetic constituents being often available, we need to address the question to find the source of the structure and its authorship.

In order to comprehend this relation tied between a creator and an automated process, we need to distinguish between the different tributary relations linking an artistic visual object and an abstract automated process. It is important to underline the implied relation might appears in both directions; an artistic object can be obtain by applying an automated process, and oppositely, an automated process can be discovered by trying to solve an artistic problem. Both sides of this equation share the common ground of creation and the results, no matter what is the original paradigm, lay on shared space of double probability: the result stands in the midway between pure technicality and art. The next step of application of the automated process is fundamentally unpredictable. For this reason, the automated process is in equal rights as much an invention as an artistic creation. Of course, once a seed bloomed, layers and layers of artistic objects, related automated process, solutions to various problems and, finally, new problems might add to the complexity of the object. We study some examples in the following paragraphs.

A practice of tiling the planarity of a wall or a floor is maybe as old as architecture itself. There exist infinitely many ways to tile the plane, but these can be grouped in finite sets when restrictions are added or when classifications are needed. If we restrict the tiling to congruent tiles, then a classification is made possible by considering reflections, rotations, translations and glide reflections of the original tile. The artist Maurelius C. Escher studied these different patterns of tiling and tried to find all possible patterns. Escher found an article by Polya and Haag on crystallography giving the complete classifications of such tilings and Escher based his next experimentations on these observations. Even if Escher have found by himself almost all the patterns, it still give a good example of an abstract mathematical problem including automatic process related to an art object. In this case, the automated process constitutes of applying infinitely many translations, rotations, reflexions or glide-reflexions, to cover a space harmonically.(Figure 4) (Schattschneider, p.23-30)

The story does not end here. Of course, different types of tessellations not involving congruent tiles have been explored as a legacy to Escher’s work and covering problem, like the Penrose aperiodic tiling and fractal tilings. The problem even evolved to include other surfaces; mathematicians and artists have explored the tiling of the sphere and this led even to tessellations on other surfaces as the hyperbolic plane or the projective plane[1]. (Figure 5) Therefore, the creation of the tiling problem is double, it includes the eventual creation of a mathematical knowledge as much as of series of artistic creations. Moreover, it creates the space of discussion in which both disciplines challenge each other.

Figure 5: Jos Leys Hyperbolic 1

A similar story is hidden behind conformal mappings. Conformal mappings are functions that project images between surfaces, possibly from itself to itself, by preserving angles of intersection between lines. Conformal mappings arises as a main interest in the study of projections and the complex plane where they naturally arise as differentiable functions. A commonly used conformal mapping from the sphere to the plane is called the stereographic projection. To obtain this projection, we can imagine we set a sphere on a plane, and from the North Pole, i.e. the more distant point from the sphere, we traces rays crossing the sphere at a point and reaching the plane at second point. The stereographic projection is obtained when mapping the whole sphere to the plane in that respect.

In the last decades, photographers like Alexandre Duret-Lutz have used projection in order obtain pleasant photographs offering different spatial perspectives. The application of the stereographic projection lead to very peculiar pictures dubbed wee planets. In these photographs, objects are grotesquely deformed while keeping an overall readability due to the conformity of the projection. Ususally, the horizon surrounding the camera morphs into the circumference a small planet on the picture, resulting in pleasant cartoonesques scenes. (Figure 6) Modern photography contains more peculiar pictures calling for stronger mathematical notions. (Lambert, 2012)

Figure 6: wee planet Alexandre Duret-Lutz

The study of functions in the complex plane led August Ferninand Möbius to the definition of Möbius transforms, a group of conformal mappings constructed from translations, rotations, dilations and inversions (which inverts the inside and outside of a circle before rotating it). These functions are conformal and they can all be link to the stereographic projection through some motions of the sphere. (Arnold and Rogness) For instance, to obtain the inversion, it is equivalent to rotate the sphere upside down before applying the stereographic projection. The use of Möbius transformations is also recognisable in the photographs of Duret-Lutz, especially when the sky stands as a disk in the middle of the picture as a result of the inversion. Interestingly, artists are now applying similar techniques to video, Ryubin Tokuzawa[1]. (http://www.ryubin.com/panolab/panoflash/#)

Other conformal mappings have been explores by photographs like Seb Pzbr or Josh Sommers. The utilisation by Sommers and Pzbr of a special composition of conformal mappings comes, though, from outside the mathematical discipline. In 1956, Escher worked on the highly complex Printing Gallery. The conformal mapping he tried to develop was so elaborate he could never finish his work, leaving a blank space in the middle. Half a century later, Lenstra and his team finally modeled the transformation Escher had in mind and, with the help of computers, they filled the blank spot. (Smit and Lenstra) The transformation, usually named the Droste effect -after on old advertisement using a self-referential figure- is now used by photographers to propose a wide range of new imageries, from self-portrait to the representation of abstract architecture. (Figure7)[1]

Figure 7 : Droste effect on architectural desing

The story of such photographs lies on multiple layers on each of which part of the authorship is diluted. It comes from a rich balance of complex numbers, functions, projections, Escher’s vision and programmers that integrated this process in code to obtain the results on photographs. This automated process and results from a 300 years old long dialogue where the authorship was constructed.

It is of prime importance to underline the presence in these pieces of art of the automated process: without the programs applying the conformal deformations, some photographs and videos, could never have existed. The creations, unreachable solely by humans, exist at the very limit of the creator’s capacity. It is the result of a tremendous collaboration where the sum worth more than the parts.

[1] For a clear introduction to the topic the reader is invited to consult John Stillwell’s work: Geometry of Surfaces, Springer, 1992.